Added tween plugin documentation

docs/included_plugins/tween.rst

@@ -0,0 +1,72 @@
+.. image:: ../_static/flatland_logo2.png
+    :width: 250px
+    :align: right
+    :target: ../_static/flatland_logo2.png
+
+Tween
+=====
+
+The tween plugin moves a body from it's start location to a relative end position.
+
+This can be done using a variety of tween modes and easings.
+
+Modes
+^^^^^
+
+- ``yoyo`` - move back and forth between the start and end position repeatedly
+- ``once`` - move to the end position and stop
+- ``loop`` - move to the end position then teleport back, then repeat indefinitely
+- ``trigger`` - move towards the end position if the "trigger_topic" ros topic recieves ``true``, move towards start otherwise.
+
+Easings
+^^^^^^^
+
+The default easing is "linear", but the following is a complete list of supported easing modes:
+
+- ``linear``
+- ``quadraticIn``, ``quadraticOut``, ``quadraticInOut``
+- ``cubicIn``, ``cubicOut``, ``cubicInOut``
+- ``quarticIn``, ``quarticOut``, ``quarticInOut``
+- ``quinticIn``, ``quinticOut``, ``quinticInOut``
+- ``exponentialIn``, ``exponentialOut``, ``exponentialInOut``
+- ``circularIn``, ``circularOut``, ``circularInOut``
+- ``backIn``, ``backOut``, ``backInOut``
+- ``elasticIn``, ``elasticOut``, ``elasticInOut``
+- ``bounceIn``, ``bounceOut``, ``bounceInOut``
+
+You can see visual examples of these easing modes `here at easings.net <http://easings.net/>`_.
+
+Configuration
+^^^^^^^^^^^^^
+
+.. code-block:: yaml
+
+  plugins:
+
+      # required, specify Tween type to load the plugin
+    - type: Tween
+
+      # required, name of the plugin, unique within the model
+      name: MyTweenPlugin
+
+      # The tween mode (documented above, default 'yoyo')
+      mode: yoyo
+
+      # The easing mode (documented above, default 'linear')
+      easing: cubicInOut
+
+      # The ROS topic name to subscribe to for 'trigger' mode ("/tween_trigger")
+      # This will respect model namespaces
+      # e.g. if this model has namespace "foo", it will publish on "/foo/tween_trigger"
+      trigger_topic: tween_trigger
+
+      # animation duration in seconds (default 1 second)
+      duration: 10
+
+      # The tween delta pose (delta x, y and angle)
+      # The following will move the object to x += 2, y += 3, and angle += 1.1
+      # relative to the start position
+      delta: [2, 3, 1.1]
+
+      # The model body to move
+      body: some_body

docs/index.rst

@@ -51,3 +51,4 @@ Class APIs are documented `here <http://flatland-simulator-api.readthedocs.io/>`
    included_plugins/tricycle_drive
    included_plugins/laser
    included_plugins/model_tf_publisher
+   included_plugins/tween